From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DFD79C4338F for ; Wed, 25 Aug 2021 07:44:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B852761214 for ; Wed, 25 Aug 2021 07:44:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238693AbhHYHov (ORCPT ); Wed, 25 Aug 2021 03:44:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:40960 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235922AbhHYHou (ORCPT ); Wed, 25 Aug 2021 03:44:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 146596127B; Wed, 25 Aug 2021 07:44:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629877444; bh=wVU9GLKhq2p6ukezJvevgnRgWmpzPM5Lh6hx13awvCo=; h=References:From:To:Cc:Subject:Date:In-reply-to:From; b=NGpKUNQ6oSgrgb1v2TMRw9Ddobcwpjz7nUAx0YJwoBAdEZQqgINe8XsKIN6JPXeVB ZdYqzG0qoTTpuBWB30J6+YfgPOwhhLXamWWF6HY96Oujq0UBhyBcNyRj2RyzAUOrnw VlYL7CarRbFVY/spLXsR3e1LY7fHHGA7rwicDIPcelou1HQmj1zIz0dLtJ42pnEGu9 ua36zxbo3e6Npz4ggYU6LZ7Uikp5oI5mZxCzgd2v05X4eR+ZJw8OlNW+X5W02hT47W 1WKOJTPfSr0C+WIxGTA5bXjVJoX0r6Wms2rFbHXhljFKW3viStjbdgNUQBrv5o8zCx cbafdrsD/jojA== References: <20210824192337.3100288-1-Nehal-Bakulchandra.shah@amd.com> <87ilzu5ap0.fsf@kernel.org> User-agent: mu4e 1.6.4; emacs 27.2 From: Felipe Balbi To: Heikki Krogerus Cc: Nehal Bakulchandra Shah , gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, kun.liu2@amd.com, alexander.deucher@amd.com Subject: Re: [RESEND PATCH 2/2] usb: dwc3: pci add property to allow user space role switch Date: Wed, 25 Aug 2021 10:43:38 +0300 In-reply-to: Message-ID: <87zgt69dfj.fsf@kernel.org> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Heikki Krogerus writes: > On Wed, Aug 25, 2021 at 08:55:41AM +0300, Felipe Balbi wrote: >> >> Hi, >> >> Nehal Bakulchandra Shah writes: >> >> > For AMD platform there is a requirement to enable user space role >> > switch from host to device and device to host as customer platform is not >> > completely capable of OTG i.e. with type C controller it does not have PD >> > to support role switching. Hence, based ACPI/EC interrupt role switch is >> > triggered by the usemode script running in background. >> usermode ? > > Couldn't you capture that ACPI/EC interrupt in kernel? > >> > Signed-off-by: Nehal Bakulchandra Shah >> >> I'm okay with this, just wondering if we need to Document the property >> somewhere. >> >> @Heikki, is there a place to document these private properties that's >> not on DT binding document? > > The build-in properties are not documented separately. I've always > tried to supply DT bindings for all new properties I've proposed. > > In this case though, do we need the new property at all? Why not just > register a normal USB role switch on this platform? It can be either a > dummy role switch that only passes the user space input to dwc3, or, > perhaps ideally, it would also be a driver that captures that ACPI/EC > event/notification and then passes the information from it to dwc3. I like the actual driver responding to EC IRQ idea. -- balbi